Direct work calculator



May 13, 1958 P. M. FRY 2,834,547

DIRECT WORK CALCULATOR Filed March 16, 1955 2 sheets-sheet 1 l? M. FRY

May 13, 1958 P. M. FRY

DIRECT woRx CALCULATOR Filed March 16, 1955 2 Sheets-Sheet 2 QYSQ,

3mm/rm F. M. FRY

United States Patent O DIRECT WORK CALCULATOR Percy M. Fry, Dallas, Tex.

Application March 16, 1955, Serial No. 494,723

4 Claims. (Cl. 23S-88) My invention relates to calculators and' computers generally, although it has particular reference to a device of this kind for use in computing or calculating the weights and surface areas of ducts which are used in connection with heating or air-conditioning systems and the like.

In the cost-estimating of different duct work installat-ions the primary consideration is the weight of the duct per lineal foot and this will necessarily depend upon the duct perimeter and the gauge of stock employed.

As is well known to those versed in the art, duct Weights per lineal foot are based upon commonly used standards and include allowance for seams. The standard width of sheets of duct work stock of different gauges is 30", and on this basis it is considered that there must `be a l lap for each sheet. This means that ducts up to 9.129" perimeter allow a l lap; those having a perimeter from 30 to 59", a 2 lap, and so on up through larger Aperimeter sizes.

Also, according to commonly used standards the gauge of stock that should be used for a round duct will depend upon its diameter while on the other hand if a duct of rectangular cross-section is being estimated, the stock 'gauge to be used depends upon the greatest wall Width dimension.

Also, in duct work estimating it is frequently necessary to know the surface area of the duct and to have this information supplied on the basis of a lineal foot, because many ducts are to be insulated.

It is, therefore, the primary object of the invention lto provide a device as characterized, which is very simple in construction, involving only two major parts and which will readily indicate to the estimator not only the gauge of stock that should be used for the round or rec tangular duct under consideration, but also the surface area and weight per lineal foot of the duct incorporating such stock.

Additionally, the invention contemplates a computer vor calculator for the stated and analogous purposes which provides indicating means defining a work area of variable size within which at different settings of the calculator is information as to ducts, for instance, of sizes which are equivalent to the size of the particular duct under consideration. This feature is important in duct `work estimating because different lengths of a particular ductmay of necessity be differently dimensioned.

4 A still further aim of the invention is to provide cer- 'tain stock gauge-indicating or analogous indicia with contrasting backgrounds, whether colored or otherwise, as a -means for indicating which gauge of stock should be used fora particular duct.

The foregoing and other objects of the invention are attained by certain novel features of construction and/ or arrangement of parts, indicia, etc., reference being had tothe accompanying drawing in connection with the detailed description thereof to follow.

In the drawing, Fig. 1 is a plan view of the assembled two-disk cornputer;

ICC

2 Fig. 2 is a plan view of the bottom disk thereof; and Fig. 3 is a sectional view taken on the line 3 3 of Fig, l.

Referring to the drawings by reference characters, nu-

merals 10 and 11 indicate the top and bottom disks, re-

spectively, which are centrally pivoted together as indicated at 12 for relative adjustment, the top disk being diametrically smaller than the bottom disk so as to expose a substantial portion of the margin of the latter,

as indicated in Figure l.

ln carrying out the invention, the minor disk-form centralrareas 10a, 11a of the respective disk-s 10, 11, provide means indicating the gauge of stock which should be used for round ducts of different diameters and the Weights of such duets per lineal foot.

The annual portions 10b, 11b of the respective disks 10, 11 which surround the minor disk-form round duct calculator areas 10a, 11a have means for selectively displaying necessary information for cost computation as to different sized ducts or the like which are rectangular in cross-section. Thus it will be seen that in my single unit I provide in effect two calculators or computers.

Referring to the round duct calculator portion 11a of the bottom disk, as disclosed in Figure 2, it will be noted that the .same provides three concentric legend-bearing circumferential areas 14, 15, 16. Related ones of the respective numeral-form legends 14a, 15a, 16a of areas 14, 15, l-which is to say those concerning a duct of a particular diameter-are arranged in aligned radial series so as to b e simultaneously displayed through the radial slot 17, which is provided in the top disk 10, as clearly shown in Figures l and 3 of the drawings.

The circular series 14 of the numeral-form legends 14a, which are innermost as shown in Figure 2, indicate duct diameters, while the next outer series of numeral legends 15a indicate gauges of stock or material that should be employed; and the outermost series of numeral legends 16a designate the weights per lineal foot of a duct. Pertinent information as to a duct of a specified diameter, is as previously noted simultaneously displayed in the top disk slot 17.

Corning now to the annular calculating or computing areas 10b, 11b for rectangular ducts, which areas surround the central disk form areas 10a, 11a, of the respective disks, 10, 11 it will be noted that the outer marginal portions thereof which define the outer margins of the respective disks 10, 11 are radially lined to divide same into marginal spaces 10c, 11C, respectively, of the same Width and which spaces are adapted to be brought into registry with one another by partial relative rotation of the disks 10, 11.

In carrying out the invention it may be noted that the outer marginal spaces 11e of the bottom disk 11 are dened by the same radial lines 11d which extend inwardly to the inner circumferential edge of the ring-form area 10b, as indicated in Figure 2, and thus divide the top surface of annular area 11b into segmental areas 11e of the same size.

Figure l indicates that each of the series of outer marginal spaces 10c, 11e bears a consecutive series of numerals designated as 21, 22, respectively, and commencing with the numeral 1. lt is important to note that the outer marginal top and bottom disk spaces 10c, 11a` are numbered (21, 22) in opposite directions. Thus, as shown in the drawings, the top disk spaces 10c are numbered in a counterclockwise direction and the bottom disk spaces 11e in a clockwise direction. The direction of spaces 10c, 11C numbering can, of course, be reversed.

The disks 10, 11 provide a top surface gap 23, 27, respectively, separating the first and last ones of the numbered spaces 10c, 11e.

The top disk 10 at the site of its numeral-separating top surface gap 23 has a radial outwardly extending tab 24 which plays over the numbered spaces 11C of the bottom disk and serves as the means for conveniently rotating the top disk 10 relatively of thebottom disk 11. Each of the-top surface gaps 23, 27, has lassociated therewith a direction of marginal space numbering direction indicator, same taking the form of arrows i25, 26, respectively. The 'indicating arrow 25 ofthe top disk -10 is imprinted on the tab 24 so as to be circumferentially aligned with the indicating arrow 26 'of the bottom disk 11, the two arrows pointing, of course, toward one another as shown.

Since the marginal spaces c, I11e of the respective top and bottom disks 10, 11 are numbered (21, 22) consecutively in opposite directions, the sum of the numerals 21, 22 of registering spaces 10c, 11C, in the work area 28 (Fig. l) Ibetween-the arrows 25, 26 will be equal.

It should be emphasized here that in the use of the computer, the numerals 21, 22 on the marginal spaces 10c, 11c of the disks 10, A11 are considered as designating different wall width dimensions of rectangular ducts or the like. Thus the sum of each pair of registering spacecarried numerals 21, 22 will be equal and will indicate ducts having the same perimeter, and of course the same wall surface area per lineal foot of duct.

Still referring to the marginal space-carried VAduct wall width-indicating numerals 21, 22, itis to be observed that the top surface gap 23 of the top disk, inwardly of the tab 24 affords space for instruction legend 23a, which states in effect that all duct sizes between the arrows or indicators 25, 26 are equivalent sizes, or 'in other words have the same perimeter length and wall surface area per lineal foot.

In actual duct construction it :frequently happens that a rectangular duct cannot be similarly 4dimensioned throughout its length owing to lack of space for Ifor other reasons. Hence it will frequently become important to have reference to equivalent sizes which are indicated in the 'marginal work area ZS-(Fig. 1)-between the arrows or indicators 25, 26.

In further carrying out the invention the top disk 10 has extending between the inner edge of its top surface gap 23 and the outer edge of its central round duct calculator portion 10a, a radial slot 29. The purpose of this slot l29 is to display therethrough data -on the bottom disk 11 which relates to at least some of the equivalent rectangular duct sizes which are indicated by the registering wall width-indicating numerals 21, 22 of the registering marginal spaces 10c, 11e in the variable work area 28 (Fig. 1) lying between, and indicated by, the arrows 25, 26, as previously explained.

Turning now to Figure l, it will be noted that the top disk 10 provides adjacent its slot 29 a radial 'series of legends numbered 30', 31, 32, 33, 34 and 35, which refer to individual ones of the several arcual series of numeralform legends 36, 37, 38, 39, 40 and 41, respectively, which are inscribed on the subjacent annular area 11b of the bottom disk 11 to be displayed through the respective adjacent portions of slot 29. The slot-adjacent legend 30 and the related bottom disk-provided legends 36 refer to square feet per lineal foot of rectangular ducts of equivalent dimensions as indicated by the numerals 21, 22 of registering spaces 10c, 11C in the work area 28 designated by the arrow form indicators 25, 26'. Similarly the slot-adjacent legend 35 and the legends of the bottom disk series 41 refer to duct perimeters indicated by different registering ones of numerals 21, 22 in the work area 28.

The slot-adjacent legends numbered 31, 32, -33-and 34, of the top disk 10 each indicate a different gauge ofstock that should be used having in mind the greatest Wall width of the duct Vunder consideration, as indicated by registering numerals 21, 22 in work area 28.

Thus, if the greatest wall width of the duct kunder consideration `(asfindicatedby registering numerals .21, 22

in work area 28) is between 1 and 34 inches then 24 gauge stock should be used; 22 gauge stock is recommended if the maximum wall width is between 35 and 60 inches; 20 gauge when such width is between 61 and 90 inches; and 18 gauge for maximum wall widths exceeding inches.

The bottom disk-information that is supplied by legends 37, 38, 39 and 40, respectively, through slot 29 opposite the respective slot-adjacent legends 31, 32, 33 and 34 is the weight per lineal foot of ducts formed from the respective stock gauges indicated by said slot-adjacent legends. But the legends 37, 38, 39, and 40, of the bottom disk 11 only supply through slot 29 at a particular relative setting of disks 10, 1'1 the lineal foot duct weight for gauges of stock which can be used for one or more of the equivalent sized ducts indicated by registering wall widths 21, 22 in the work area 28 between arrows 25, 26.

An important feature of the invention is -the use of contrasting surface shading or colors as a part-of the Stock gauge selection aid or indicator which is employed and will now be described.

In carrying out the above noted phase of the invention, I provide the top surface of the bottom disk 11 with four circumferential series of spaces which are indicated vas 42, 43, 44 and 45, respectively. Corresponding spaces of the respective series 42, 43, 44, 45 are radially aligned, as shown in Fig. 2, and are simultaneously displayed in the outer portion of the top disk-provided slot 29 opposite the top disk-provided legends 46, 47, 48 and y49, respectively. Certain consecutive ones, or sets of lthe spaces of the respective series are differently colored or shaded as indicated at 42a, 43a, 44a and 45a, respectively, to correspond to the stock 'gauge-indicating c'olor notations which are referred to in the respective registering slot-adjacent legends 46, 47, 48, and 49, and which designate the respective stock gauges by different colors.

The relative location of the various bottom disk-.provided colored space sets 42a, 43a, 44a, 45a With'respect to registering pairs of the marginal wall width-indicating numerals 21, 22 in work area 28 (Fig. 2) between arrows 25, 26, is such that a particular one of the gauge-indicating colored spaces 42a, 43a, 44a, or'45a will show up infslot 29 only if the indicated gauge of stock can be used for at least one of the equivalent sized ducts designated by registering marginal numerals 21, 22 in said work areas.

Also, by preference, different lengths of 4the marginal spaces 10c, llc of disks 10, 11, will be differently'colored according to the duct wall width-indicating numerals 21 (or 22) thereon. Thus, in each instance -th'e marginal 10c, llc, spaces bearing wall width numerals from f1-34 will be colored brown to correspond to the color of bottom disk space set 42a to refer to 24 gauge stock; marginal spaces 10c, 11C, numbered from 3S-60 will be colored red to correspond to the color of the b'ottom disk space set 43a and indicates 22 gauge stock; -and marginal spaces numbered from 6G-90 will be colored blue to correspond to the color of bottom disk space set 44a and indicates 20 gauge stock; and nally marginal spaces 10c, 11e numbered above 90 will be colored green to correspond to bottom disk space set 45a and designate 18 gauge stock. So it is seen that the user can also tell what gauge of stock can possibly be used in a given instance by simply noting what colors appear in vmarginal spaces 10c, 11c of the work -area 28 at any given yrelative setting of disks 10, v11--and this independently of the same information which is supplied by any of the bottom disk-provided colored spaces 42a, 43a, 44a or 45a which appear in slot 29 opposite the respective legends, 46, 47 48er 49 at such setting.

As a means for further facilitating the selection ofthe .proper gauge of stock to`be employed in the fabrication of the particular duct under consideration as represented by the numeral-form wall width-indicating `legends 21, 22 of registering outer vmarginal spaces 10c, 11c of therespective top and bottom disks, 10, 11, I provide the slotf one (see Fig. l) which is l X 17".

adjacent stock gauge-indicating legends 31, 32, 33, 34 with colored gauge-indicating backgrounds.

Thus, the background of legend 31 would be green" to refer to the 18 gauge stock and to the various lineal foot weights stock and to the various lineal foot weights therefor supplied by the series of bottom disk legends 37; and the respective backgrounds of legends 32, 33 and 34 would be blue, red and brown, to refer to the bottom disk-supplied information as weights per lineal foot of 20 gauge, 22 gauge and 24 gauge stock, respectively.

The operation of the calculator will now be summarized with examples of different disk settings.

First vas to the centralfround duct calculator portion a, 10b. The diameter of the duct to be estimated can always be ascertained and is allthe information the operator needs. Suppose that the diameter is 21", as it is in Fig. l setting. The device supplies the information that 24 gauge stock should be used and that the weight of the same is 6.67 pounds per lineal foot. Therefore, all the estimator has to do is to multiply the lineal feet of duct by 6.67 and he knows the amount of stock required.

Now as to figuring rectangular ducts and for instance The marginal wall width-indicating numerals l0 and 17" (of series 21, 22) are brought into registry as in Fig. l.

The bottom disk 10 indicates in slot 29 that such a duct(or any duct indicated in work area 28) will have 4.5 square feet per lineal foot. This information is important if the duct is to be insulated. Then, too, the bottom disk supplies in slot 29 the semi-perimeter dimension as 27, from which the perimeter is determined to be 54" by the simple operation of multiplying 27l by two.

Since the operator knows that the gauge of stock to be used depends on the greatest wall width of the 17 x l0" duct under consideration he examines the slot adjacent gauge-indicating legends 31, 32, 33 and 34. A glance tells him that since the greatest wall width is 17, he will use 24 gauge stock as designated by legend 34; and the bottom disk legend 41, showing through slot 29 opposite 34, indicates that his duct using the prescribed 24 gauge stock will weigh 5.6 pounds per lineal foot. With this information it is only necessary to multiply 5.6 by the length of the duct to iind out how much material will be required.

Some times the marginal work area 28 between indicators 25, 26 will refer to such a range of wall widths represented by registering numerals 21, 22 as to mean that a selection between two or more gauges of stock (see 31, 32, 33 and 34) must be made. Thus, if the rectangular duct being figured is 47 x 20 the slot 29 will show gauge weights not only for 24 gauge stock (34) but also for 22 gauge (33) and 20 gauge (32). The weights of 24 gauge will be 13.9 lbs. per lineal foot; 16.2 lbs. for 22 gauge and 19.69 lbs. for 2O gauge. However, since the greatest wall Width of the duct under consideration is 47", the estimator knows from an inspection of the slot-adjacent legend 33 that 22 gauge stock should be used.

The use of color background panels for the slot-adjacent gauge-indicating legends 31, 32, 33, and 34 and for 46, 47, 48 and 49; and the use of corresponding gauge-indicating color spaces 42, 43, 44, 45 opposite 46, 47, 48 and 49, respectively, helps the estimator to avoid error in selecting the gauge of stock to be used. Also, coloring different series of marginal spaces 10c, 11C to indicated related gauge weights is helpful to the same end.

From the foregoing it is believed that my advance in the art will be fully understood and appreciated by those versed in the art. While I have illustrated the invention in concrete form, as required by the patent statutes, it is to be understood that same is susceptible of various other mechanical expressions within the spirit and scope of the subject matter claimed hereinafter.

Having thus described my invention, what I claim is:

l. A calculator for duct work estimating and for other purposes comprising in combination, concentric top and bottom disks, means pivotally connecting said disks at centers for relative rotation, the bottom disk being diametrically larger than the top disk, each disk having at its top surface an outer marginal and circumferentially extending series of registerable indicia-bearing spaces, each disk also providing a top surface gap separating the rst and the last of the marginal spaces of its said series, an indicator on the top surface of each disk adjacent the site of the related top surface gap, said indicators extending in opposite circumferential directions to define a marginal space-provided work area therebetween, adjacent radial rows of indicia legends on said bottom disk, said rows of bottom disk-carrying indicia being corelated to different work area-delined groups of registering marginal indicia, and said top disk having slot means through which the rows of bottom disk indicia are selectively displayed.

2. A calculator as set forth in claim l, and including a radially extending actuating tab projecting from the outer margin of said top disk and providing an extension of the top surface gap of said top disk and the indicator of said top disk carried by said tab and in substantial circumferential alignment with the indicator of the bottom disk so as to unmistakeably indicate said work area at a glance.

3. A calculator for use in computing the quantity of stock required in the construction of diierent rectangular duct work installations of various lengths and cross-sectional dimensions comprising in combination, concentric top and bottom disks, means pivotally connecting said disks at their centers for relative rotation, the bottom disk being diametrically larger than the top disk, each disk having at its top surface an outer marginal and circumferentially extending series of registerable and consecutively numbered spaces indicating different duct wall widths, each disk also providing atop surface gap separating the first and last space of its said series and the consecutive numbering of the spaces of the respective series commencing with the same number and extending in opposite circumferential directions; an indicator on the top surface of each disk adjacent the site of the related top surface gap between the lowest and highest numbered space of its marginal numbered space series and indicating the direction of numbering of the spaces thereof, said indicators designating a marginal registering spacedefined work area of variable length therebetween on Said disks, adjacent radial rows of indicia legends on said bottom disk and co-related to rectangular ducts dimensioned as indicated by any two wall width-indicating numbers of the registering marginal disk spaces of said work area between said indicators at all relative adjustments of said disks, said top disk having a radially extending slot selectively displaying said radial indicia rows of said bottom disk, and radially spaced indicia items on said top disk adjacent said slot, said respective indicia items arranged opposite and co-related to different slot-exposed indicia legends of the respective bottom disk rows.

4. A calculator for use in computing the quantity of stock required in the construction of different rectangular duct work installations of various lengths and crosssectional dimensions comprising in combination, concentric top and bottom disks, means pivotally connecting said disks at their centers for relative rotation, the bottom disk being diametrically larger than the top disk, each disk having at its top surface an outer marginal and circumferentially extending series of registerable and consecutively numbered spaces indicating different duct wall widths, each disk also providing a space separating the rst and last space of its said series and the consecutive numbering of the spaces of the respective series extend ing in opposite circumferential directions, a radially eX- tending tab projecting from the outer margin of the top disk at the site of its space, an indicator on said bottom disk space and on said top disk tab and indicating the direction of numbering of marginal spaces of said respective disks, said indicators being substantially circumferentially aligned with each other and with the marginal spaces'of the bottom disk whereby to designate a marginal Work-area therebetween on said disks, adjacent radial rows o'f lindicia legends on said bottom disk land co-related to rectangular ducts dimensioned as indicated by the two wall width indicating numbers of the vregistering marginal disk spaces of said work area between said indicators, said top -disk yhaving Va radially extending slot selectively displaying said radial indicia rows of said bottom disk, and indicia items on said top diskadjacent said slot, said respective indicia items arranged opposite and co-related to different indicia legends of the respective bottom disk rows when the latter are displayed `in Said slot.

References Cited in the 'ile of this patent UNITED STATES PATENTS 634,779 Tregonig Oct. 10, 1899 704,979 Terranas July 15, 1902 778,790 `Merrill Dec. 27, 1904 784,660 Chritton Mar. 14, 1905 1,262,635 Cady Apr. 16, 1918 2,039,921 Murphy May 5, 1936 OTHER REFERENCES Pages 40 and 41 of section 4, of Heating and Ventilating Engineering Handbook, by Clifford Stock, published in 1948 by -the Industrial Press, 148 Lafayette Street, 'New York 13, N. Y. 

